Halogen treatment of combustion chambers



United States Patent HALOGEN TREATMENT OF COMBUSTION CHAMBERS Charles G. Grimes, 3735 N. College Ave., Indianapolis, Ind.

No Drawing. Filed Feb. 10, 1958, Ser. No. 714,057

1 Claim. (Cl. 117-62) This invention relates toa novel method of improving the characteristics of metallic combustion chambers and to the improved combustion chambers thus made, this application being a continuation-in-part of my co-pending application Serial No. 653,518, filed April 18, 1957, now abandoned, entitled Heat-Treating Process.

It is the object of this invention to provide a process for improving the characteristics of the combustion chambers of internal combustion engines and of furnaces by treating the said combustion chambers so as to' alter favorably their surfaces for the combustion of hydrocarbon fuels. It is another object of this invention to provide internal combustion engines containing combustion chambers of increased efficiency. Other objects of this invention will be apparent from the disclosure hereinafter set forth.

In accordance with the above and other objects, this invention provides a process for improving the characteristics of metallic combustion chambers which comprises treating the interior surfaces of the said combustion chambers with halogen-containing organic compounds. In addition, this invention provides internal combustion engines or furnaces containing metallic combustion chambers, the interior surfaces of which have been treated with halogen-containing organic compounds.

The halogenated substances which can be employed in the process of the invention are exemplified by the halogenated hydrocarbons such as carbon tetrachloride, carbon tetrabromide, carbon tetrafluoridc, bromotrifluoromethane, trichlorofiuoromethane, dichlorodifluoromethane, dibromodifluoromethane, chlorotrifluoromethane, trichlorotrifluoroethane, dichlorotetrafiuoroethane, silicon tetrachloride and the like. Chlorine and fluorine alone can be used with satisfactory results.

The novel process of this invention is customarily carried out as follows: The combustion chamber to be treated is brought to a temperature in the range of from about 120 C. to 300 C. by placing it in an ordinary furnace or oven maintained in that temperature range or by operation of the combustion chamber itself in conjunction with the burner or combustion means usually associated therewith. Thus, for example, if an oil-stoked furnace is to be treated, the oil burner is operated until the desired temperature has been reached. Similarly, a gasoline engine or gas turbine engine can be operated until the proper temperature is produced in the areas to be treated. When the desired temperature has been reached, the halogen or halogenated material which is to be used is introduced into the combustion chamber in vapor form. Such vapors can be produced by heating the material to be employed to a temperature above its boiling point, but obviously simply introducing solid or liquid substances into the hot furnace or heated combustion. chamber will produce the desired result. Contact with the vapors of the halogen compound employed is continued for about minutes to minutes, while maintaining the temperature of the surfaces to be treated at the selected temperature.

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The process as outlined above is applied most'advan tageously and with the best'results to metallic combustion chambers which have undergone considerable use and have a deposit of carbonygums and other unburned hydrocarbon fuel by-products or residues coating their inner surfaces. New unused combustion chambers can also be treated in accordance with my novel process with a resulting increase in efficiency of operation. However, in the case of new combustion chambers, I prefer to pretreat the interior surfaces prior to a halogen treatment as follows: A mixture containing asource of carbon particles such as graphite or carbon black and an organic coating such as spar varnish or shellac is painted on the interior surface of the combustion chamber and allowed to dry, thus forming a deposit which is similar in character to that found in oil furnaces and gasoline engines after long use. The new unused combustion chamber coated in the above manner can then be treated by a halogen compound in the vapor phase as outlined hereinabove.

With new unused combustion chambers, an alternative halogen treatment process is available. This alternative process comprises adding a liquid halogen containing compound to the graphite-varnish mixture, painting this new mixture on the interior surface, and letting it dry as before. The halogen compound is then in situ and in intimate contact with the simulated carbon deposit. Bringing the thus coated combustion chamber up'to the desired temperature accomplishes essentially the same efficacious results as does the halogen treatment previously described in which the halogen-containing organic compound is introduced into the heated combustion chamber in vapor phase.

Metallic combustion chambers which have been treated with vapors of halogens or halogen compounds in accordance with the process of the invention have highly advantageous characteristics. They are able to bring about more efficient and more complete combustion of the hydrocarbons burned therein, They also are less subject t'o the further'deposit of carbon on the surfaces of the combustion chambers which are exposed to thejflame. The rate of combustion is reduced in the treated chambers and formation of toxic by-products such as carbon monoxide is reduced. In the case of internal combustion engines, the combustion chambers ofwhichhav'e been treated by'the process of the invention, compression ratios and "the degree of spark advance can be. increased, without causing pre-ignition or spark knock. v

Incidental reactionor alloying of the halogen-carrying element-carbon, silicon or the likewith the metal of the combustion chamber, which usually contains iron, is not believed to play a major role in the accomplishment of the result outlined above, particularly when it is considered that any internal combustion engine or furnace is constantly operated in the presence of carbon compounds in the vapor phase.

The following examples will specifically illustrate the process of halogen treating metallic combustion chambers.

Example 1 0 Halogen treatment of used gasoline combustion engine,

tetrachloride is injected into the manifold through the disassembled air cleaner. C. The carbon tetrachloride is injected in the amoun of 6 cc. at 15 second intervals until 120 cc. of carbon tetrachloride has been injected. (Explo-v sion warning.) The heat-treated engine will performe with the effect of upgrading octane gasoline (containing 3 cc. tetraethyl lead) vapproximately grade 85 octane gasoline (containing no tetraethyl lead) approximately 11 octane. Hence, this test shows favorable'results using motor fuel containing tetraethyl lead, but it shows more conclusively that the tetraethyl lead is unnecessary. The toxic compounds used in the combustion chamber heat-treating process remain in the combustion chamber permanently, whereas in vthe present widespread use of tetraethyl of lead the toxic compounds are spent and released into the atmosphere, creating a possible health hazard.

The surface of the combustion chamber of the heat- .treated engine will not collect carbon. The spark plugs will not foul nor burn with long use. Operation on kerosene can be satisfactory except for poor cold weather starting. l Example 2 Halogen treatment of used gasoline or diesel engine, using bromotrifiuoromethane:

A. The engine is started and operated until combustion chamber reaches 120 C. or above.

B. Engine speed is increased. Bromotrifluoromethane is injected into the manifold in amounts of 4 cc. at 15 second intervals. This is repeated thereafter until 80 cc. has been injected. (Explosion warningalso poisonous fumes.)

Example 3 Halogen treatment of used gasoline or diesel engine, us-

. ing compressed chlorine or fluorine gas:

A. Engine started and operated until combustion chamber reaches 120 C. or over.

B. Engine speed is increased and compressed chlorine or fluorine is released into manifold.

C. Chlorine or fluorine is released into manifold in spurts, at 30 second intervals for approximately 15 minutes.

A Example 4 Treatment of a used oil-fired furnace, using carbon tetrachloride or other comparable halogen compounds:

A. The house is vacatedof humans and pets, windows are opened. B. Furnace burner is made to burn steadily until combustion chamber reaches 150' C. 'C. Furnace oil burner is made to continue burning.

7 ,067 V v I 6 octane; however, it Will.up-..

Then 4 cc. carbon tetrachloride or comparable The injections are made at 30 4 The process is complete. and. after. th 1 3591 88 been aired the windows may be closed.

After the oil burner combustion chamber is heattreated the burner roar is greatly reduced. Tests showed the combustion rateto be slower and combustion more complete. The amount of burner air-intake was increased without causing the usual loud roar and rough combustion. These are all beneficial results.

Example 5 Halogen treatment of new gasoline or diesel engine, using carbon tetrachloride:

Beforefinal engine assembly, interior surfaces of cylinders are coated with a mixture of graphite and spar var nish. Coating is allowed to dry. Engine is assembled using interior coated cylinders.

Halogen treatment is carried out as in Example 1.

Example 6 7 Halogen treatment of new gasoline or diesel engine, using carbon tetrachloride:

.tures ranging from degrees C to 300 degrees C., continuing the heatwithin said ranges and applying to said walls by injection for a period of time not exceeding twenty minutes a halogenated organic compound at intter vals of 15 to 30 seconds until 120 cc. to cc. of said compound have been applied to said walls.

References Cited in the file of this patent UNITED STATES PATENTS Murphy et al. June 11, 1940 2,479,901 Calingaert Aug. 23, 1949 "2,479,902 Calingaert Aug..23, 1949 2,759,804 Sherman Aug. 21, 1956 2,784,160 Blaker Mar. 5, 1957 Rounds et al. Dec. 2, 

